Methods of treating chronic obstructive pulmonary disease

ABSTRACT

The methods and devices disclosed altering gaseous flow within a lung to improve the expiration cycle of individuals having Chronic Obstructive Pulmonary Disease.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/633,902, filed Aug. 4, 2003, which is a continuation of U.S. patentapplication Ser. No. 09/633,651 filed Aug. 7, 2000 now U.S. Pat. No.6,692,494, which claims the benefit under 35 U.S.C. § 119(e) of U.S.Provisional Patent Application No. 60/147,528 filed Aug. 5, 1999 and60/176,141 filed Jan. 14, 2000, all of which are incorporated in theirentirety.

FIELD OF THE INVENTION

The invention relates to methods and devices to allow expired air ableto pass out of the lung tissue to facilitate both the exchange of oxygenultimately into the blood and/or to decompress hyper-inflated lungs. Theinvention also directed to methods and devices to altering gaseous flowwithin a lung to improve the expiration cycle of an individual,particularly individuals having Chronic Obstructive Pulmonary Disease(COPD).

BACKGROUND OF THE INVENTION

The term “Chronic Obstructive Pulmonary Disease” (COPD) is generallyused to describe the disorders of emphysema and chronic bronchitis.Previously, COPD was also known as Chronic Obstructive Lung Disease(COLD), Chronic Airflow Obstruction (CAO), or Chronic Airflow Limitation(CAL). Some also consider certain types of asthma to fall under thedefinition of COPD. Emphysema is characterized by an enlargement of airspaces inside the lung. Hence, Emphysema is an anatomic definition andit can only be presumed in a living patient. Chronic bronchitis ischaracterized by excessive mucus production in the bronchial tree.Chronic bronchitis is a clinical definition and denotes thoseindividuals who meet criteria defining the disease. It is not uncommonfor an individual to suffer from both disorders.

In 1995, the American Lung Association (ALA) estimated that between15-16 million Americans suffered from COPD. The ALA estimated that COPDwas the fourth-ranking cause of death in the U.S. The ALA estimates thatthe rates of emphysema is 7.6 per thousand population, and the rate forchronic bronchitis is 55.7 per thousand population.

Those inflicted with COPD face disabilities due to the limited pulmonaryfunctions. Usually, individuals afflicted by COPD also face loss inmuscle strength and an inability to perform common daily activities.Often, those patients desiring treatment for COPD seek a physician at apoint where the disease is advanced. Since the damage to the lungs isirreversible, there is little hope of recovery. Most times, thephysician cannot reverse the effects of the disease but can only offertreatment and advice to halt the progression of the disease.

To understand the detrimental effects of COPD, the workings of the lungsrequires a cursory discussion. The primary function of the lungs is topermit the exchange of two gasses by removing carbon dioxide from venousblood and replacing it with oxygen. Thus, to facilitate this exchange,the lungs provide a blood gas interface. The oxygen and carbon dioxidemove between the gas (air) and blood by diffusion. This diffusion ispossible since the blood is delivered to one side of the blood-gasinterface via small blood vessels (capillaries). The capillaries arewrapped around numerous air sacs called alveoli which function as theblood-gas interface. A typical human lung contains about 300 millionalveoli.

The air is brought to the other side of this blood-gas interface by anatural respiratory airway, hereafter referred to as a natural airway orairway, consisting of branching tubes which become narrower, shorter,and more numerous as they penetrate deeper into the lung. Specifically,the airway begins with the trachea which branches into the left andright bronchi which divide into lobar, then segmental bronchi.Ultimately, the branching continues down to the terminal bronchioleswhich lead to the alveoli. Plates of cartilage may be found as part ofthe walls throughout most of the airway from the trachea to the bronchi.The cartilage plates become less prevalent as the airways branch.Eventually, in the last generations of the bronchi, the cartilage platesare found only at the branching points. The bronchi and bronchioles maybe distinguished as the bronchi lie proximal to the last plate ofcartilage found along the airway, while the bronchiole lies distal tothe last plate of cartilage. The bronchioles are the smallest airwaysthat do not contain alveoli. The function of the bronchi and bronchiolesis to provide conducting air ways that lead inspired air to thegas-blood interface. However, these conducting airways do not take partin gas exchange because they do not contain alveoli. Rather, the gasexchange takes place in the alveoli which are found in the distal mostend of the airways.

The mechanics of breathing include the lungs, the rib cage, thediaphragm and abdominal wall. During inspiration, inspiratory musclescontract increasing the volume of the chest cavity. As a result of theexpansion of the chest cavity, the pleural pressure, the pressure withinthe chest cavity, becomes sub-atmospheric with respect to the pressureat the airway openings. Consequently, air flows into the lungs causingthe lungs to expand. During unforced expiration, the expiratory musclesrelax and the lungs begin to recoil and reduce in size. The lungs recoilbecause they contain elastic fibers that allow for expansion, as thelungs inflate, and relaxation, as the lungs deflate, with each breath.This characteristic is called elastic recoil. The recoil of the lungscauses alveolar pressure to exceed the pressure at airway openingscausing air to flow out of the lungs and deflate the lungs. If thelungs' ability to recoil is damaged, the lungs cannot contract andreduce in size from their inflated state. As a result, the lungs cannotevacuate all of the inspired air.

Emphysema is characterized by irreversible damage to the alveolar walls.The air spaces distal to the terminal bronchiole become enlarged withdestruction of their walls which deteriorate due to a bio-chemicalbreakdown. As discussed above, the lung is elastic, primarily due toelastic fibers and tissues called elastin found in the airways and airsacs. If these fibers and tissues become weak the elastic recoil abilityof the lungs decreases. The loss of elastic recoil contributes to moreair to entering the air sacs than can exit preventing the lungs fromreducing in size from their inflated state. Also, the biochemicalbreakdown of the walls of the alveolar walls causes a loss of radialsupport for airways which results in a narrowing of the airways onexpiration.

Chronic bronchitis is characterized by excessive mucus production in thebronchial tree. Usually there is a general increase in bulk(hypertrophy) of the large bronchi and chronic inflammatory changes inthe small airways. Excessive amounts of mucus are found in the airwaysand semisolid plugs of this mucus may occlude some small bronchi. Also,the small airways are usually narrowed and show inflammatory changes.

In COPD, a reduction in airflow arises as a result of 1) partial airwayocclusion by excess secretions, 2) airway narrowing secondary to smoothmuscle contraction, bronchial wall edema and inflation of the airways,and 3) reduction in both lung elasticity and tethering forces exerted onthe airways which maintain patency of the lumen. As a result of theCOPD, the airways close prematurely at an abnormally high lung volume.As mentioned above, in an emphysematous lung there is a decrease of lungparenchyma as there are larger and fewer air sacs. Thus, there is adecrease in the amount of parenchymal tissue which radially supports theairways. This loss of radial traction allows the airway to collapse moreeasily. As lung recoil decreases and airway closure occur at higher lungvolumes, the residual volume of gas in the lung increases. Consequently,this increased residual gas volume interferes with the ability of thelung to draw in additional gas during inspiration. As a result, a personwith advanced COPD can only take short shallow breaths.

One aspect of an emphysematous lung is that the flow of air betweenneighboring air sacs, known as collateral ventilation, is much moreprevalent as compared to a normal lung. Yet, while the resistance tocollateral ventilation may be decreased in an emphysematous lung thedecreased resistance does not assist the patient in breathing due to theinability of the gasses to enter and exit the lungs as a whole.

Currently, although there is no cure for COPD, treatment includesbronchodilator drugs, and lung reduction surgery. The bronchodilatordrugs relax and widen the air passages thereby reducing the residualvolume and increasing gas flow permitting more oxygen to enter thelungs. Yet, bronchodilator drugs are only effective for a short periodof time and require repeated application. Moreover, the bronchodilatordrugs are only effective in a certain percentage of the population ofthose diagnosed with COPD. In some cases, patients suffering from COPDare given supplemental oxygen to assist in breathing. Unfortunately,aside from the impracticalities of needing to maintain and transport asource of oxygen for everyday activities, the oxygen is only partiallyfunctional and does not eliminate the effects of the COPD. Moreover,patients requiring a supplemental source of oxygen are usually neverable to return to functioning without the oxygen.

Lung volume reduction surgery is a procedure which removes portions ofthe lung that are over-inflated. The improvement to the patient occursas a portion of the lung that remains has relatively better elasticrecoil which allows for reduced airway obstruction. The reduced lungvolume also improves the efficiency of the respiratory muscles. However,lung reduction surgery is an extremely traumatic procedure whichinvolves opening the chest and thoracic cavity to remove a portion ofthe lung. As such, the procedure involves an extended recovery period.Hence, the long term benefits of this surgery are still being evaluated.In any case, it is thought that lung reduction surgery is sought inthose cases of emphysema where only a portion of the lung isemphysematous as opposed to the case where the entire lung isemphysematous. In cases where the lung is only partially emphysematous,removal of a portion of emphysematous lung increases the cavity area inwhich the non-diseased parenchyma may expand and contract. If the entirelung were emphysematous, the parenchyma is less elastic and cannotexpand to take advantage of an increased area within the lung cavity.

Both bronchodilator drugs and lung reduction surgery fail to capitalizeon the increased collateral ventilation taking place in the diseasedlung. There remains a need for a medical procedure that can alleviatesome of the problems caused by COPD. There is also a need for a medicalprocedure that alleviates some of the problems caused by COPDirrespective of whether a portion of the lung, or the entire lung isemphysematous. The production and maintenance of collateral openingsthrough an airway wall which allows expired air to pass directly out ofthe lung tissue responsible for gas exchange. These collateral openingsultimately decompress hyper inflated lungs and/or facilitate an exchangeof oxygen into the blood.

SUMMARY OF THE INVENTION

This invention relates to devices and methods for altering gaseous flowin a diseased lung. In particular, the inventive method includes the actof improving gaseous flow within a diseased lung by the step of alteringthe gaseous flow within the lung. A variation of the inventive methodincludes the act of selecting a site for collateral ventilation of thediseased lung and creating at least one collateral channel at the site.The term “channel” is intended to include an opening, cut, slit, tear,puncture, or any other conceivable artificially created opening. Afurther aspect of the invention is to locate a site within a portion ofa natural airway of the respiratory system of the patient having thediseased lung. The portion of the natural airway selected for thecreation of the collateral channels may be, for example, the bronchi,the upper lobe, the middle lobe, the lower lobe, segmental bronchi andthe bronchioles.

A variation of the invention includes selecting a site for creating acollateral channel by visually examining areas of collateralventilation. One variation includes visually examining the lung with afiber optic line. Another example includes the use of non-invasiveimaging such as x-ray, ultrasound, Doppler, acoustic, MRI, PET computedtomography (CT) scans or other imaging. The invention further includesmethods and devices for determining the degree of collateral ventilationby forcing gas through an airway and into air sacs, reducing pressure inthe airway, and determining the reduction in diameter of the airwayresulting from the reduction in pressure. The invention further includesmethods and devices for determining the degree of collateral ventilationby forcing a volume of gas within the lung near to the airway andmeasuring pressure, flow, or the return volume of gas within the airway.The invention also includes methods and devices for occluding a sectionthe airway and determining the degree of collateral ventilation betweenthe occluded section of the airway and the air sacs.

An important, but not necessarily critical, portion of the invention isthe step of avoiding blood vessels or determining the location of bloodvessels to avoid them. It is typically important to avoid intrapulmonaryblood vessels during the creation of the collateral channels to preventthose vessels from rupturing. Thus, it is preferable to avoidintrapulmonary or bronchial blood vessels during the creation of thecollateral channels. Such avoidance may be accomplished, for example bythe use of non-invasive imaging such as radiography, computed tomography(CT) imaging, ultrasound imaging, Doppler imaging, acoustical detectionof blood vessels, pulse oxymetry technology, or thermal detection orlocating. The avoidance may also be accomplished using Doppler effect,for example transmission of a signal which travels through tissue andother bodily fluids and is reflected by changes in density that existbetween different body tissue/fluids. If the signal is reflected fromtissue/fluid that is moving relative to the sensor, then the reflectedsignal is phase shifted from the original signal thereby allowing fordetection. The invention includes devices having at least one sensor forthe above described imaging methods. In variations of the inventionhaving multiple sensors, the sensors may be arranged in a linear patternor in an array pattern. Also, the invention may have a mark to serve asa reference point while the device is remotely viewed.

The invention may include adding an agent to the lungs for improving theimaging. For example, a gas may be inserted into the lungs to providecontrast to identify hyperinflation of the lungs during an x-ray orother non-invasive imaging. For example, ¹³³Xe (Xenon 133) may be usedas the agent. Also, a contrast agent may help in identifying bloodvessels during CT scans. Another example includes inserting a fluid inthe lungs to couple an ultrasound sensor to the wall of an airway.

Another variation of the act of looking for blood vessels includesinsertion of a probe into a wall of the natural airway for the detectionof a blood vessel. Such a probe may, for example, detect the presence ofa blood vessel upon encountering blood such as when the probe isinserted into a vessel. The probe may also use ultrasonic detection todetermine the location of a vessel. For example, ultrasound may be usedto determine changes in composition of the tissue beyond the airway wallfor determination of the location of a vessel. A probe may, for example,use low frequency radio energy to induce heat at a point and determinethe presence of a vessel by measuring a change in temperature due to theconduction of heat by the blood flowing within the vessel. Anothervariation is that the probe could detect changes in impedance given apre-arranged discharge of current through the bloodstream. It is alsocontemplated that the probe is used, for example, purposely to find theblood vessel, so that an alternative site may be selected at a safedistance from the vessel.

Another variation of the invention is via the delamination of the bloodvessel and the wall of an airway. This delamination may occur in manyways. For instance, the airway may be expanded until the vesselseparates from the wall of the airway. Or, a vacuum may be appliedwithin the interior of the airway using, for example, two occlusiveballoons or the like to isolate a portion of the airway and apply avacuum. The vacuum between the balloons constricts the diameter of theairway by collapsing the walls of the airway until the exterior wallsseparate from any blood vessel.

The invention may also include providing a remotely detectable signal toindicate the presence or absence of any blood vessels at the targetsite. The invention also includes methods and devices for marking adesired site for the creation of a collateral channel.

The invention also includes the act of creating one or more collateralchannels within the respiratory system of the individual. The collateralchannels may have a cross sectional area anywhere between 0.196 mm² to254 mm². Any subset of narrower ranges is also contemplated. Thecollateral channels may also extend anywhere from immediately beyond theepithelial layer of the natural airway to 10 cm or more beyond theepithelial layer. The channel or channels should be created such thatthe total area of the channel(s) created is sufficient to adequatelydecompress a hyperinflated lung. The channel may be, for example, in theshape of a hole, slit, skive, or cut flap. The channel may be formed bythe removal of any portion of the airway wall; e.g., a circumferentialor arc-shaped ring of material may be removed to form the channel. Suchan excised periphery may be for example, perpendicular or at angled withrespect to the axis of the airway.

Another variation of the invention involves creation of a collateralchannel by creating an incision in a natural airway and using a bluntmember to push the vessel away from the path of a collateral channel.Another variation of forming the collateral channel is, for example, byuse of a mechanical process such as dilation, cutting, piercing, orbursting. For example, a balloon may be used to expand an incision madein the natural airway or the natural airway itself until a collateralchannel is opened. Or, a mechanical cutter or piercing tool could beused to open and create the collateral channel. Another variation forcreating a collateral channel includes making an incision in the naturalairway and placing the wall of the airway in tension, then advancing ablunt instrument into the incision.

Also, it is anticipated that along with any method of creating acollateral channel any loose material or waste generated by the creationof the collateral channel is optionally removed from the airway.

Another variation for creating the collateral channel is the creation ofthe airway using electric energy, for example radio frequency. Or, forexample, ultrasonic energy, a laser, microwave energy, chemicals, orcryo-ablative energy may be used to form a collateral channel as well. Afeature of these methods often includes creation of a hemostasis in theevent that any blood vessel is punctured. For example, use of RF energyprovides a hemostasis given a puncture of a vessel by using heat to sealthe vessel. Similarly, an ultrasonic scalpel also provides an area ofhemostasis in case the vessel is punctured. It is understood that anycombination of different methods may be used for forming a single ormultiple collateral channels. A variation of the invention includes alimiter for limiting the depth of a collateral channel.

A variation of the inventive device includes a device that detectsmotion within tissue using Doppler measurements. The device may includea flexible member having a transducer assembly that is adapted togenerate a source signal and receive a reflected signal. The inventivedevice may also comprise a hole-making assembly that is adapted tomaking collateral channels within tissue. The transducer assembly mayinclude an acoustic lens which enables the transmission and detection ofa signal over a tip of the device. The hole-making assembly may be an RFdevice and use portions of the tip of the device as RF electrodes, orthe hole-making assembly may use ultrasound energy to make the hole.

Another variation of the invention includes the act of inserting animplant or conduit within a collateral channel to maintain the patencyof the channel over time during the expiration cycle of the lung. Aconduit could, for example, have distal and proximal ends with a walldefining a lumen extending between the ends. The conduit could have, forexample, a porous wall permitting the exchange of gasses through thewall. The conduit may, for example, be comprised of a material such aselastomers, polymers, metals, metal alloys, shape memory alloys, shapememory polymers, or any combination thereof. A variation of theinvention includes an expandable conduit, either one that isself-expanding, or one that expands in diameter in relation to anyapplied radial, or axial force. For example, the conduit may be expandedinto an opening of the natural airway upon the inflation of a balloon. Avariation of the conduit may include the use of flanges or anchors tofacilitate placement of the device within an airway. Another variationof the conduit includes placing a one-way valve within the conduit.Another variation includes using a self cleaning mechanism within theconduit to clear accumulating debris.

The inventive conduit may be, for example, removable or permanent. Also,another variation of the device includes a means for inserting theconduit within a collateral channel. The conduit may be constructed toallow for passage of gasses through its wall, for example, the conduitmay have a wall consisting of a braid. A variation of the conduit may belocated through an opening in a wall of an airway and engage both aninside and outside of the wall. Another variation of the conduitincludes a distal end having a porous member and a proximal end having agrommet member which engages an opening in a wall of the natural airway.Yet another variation of the implant, for example, comprises anexpandable conduit-like apparatus which could bridge an opening within awall of a natural airway. Another variation includes the conduit-likeapparatus having a cutting portion exterior to the device whereinexpansion of the device pierces the wall of the natural airway andcreates a collateral channel.

An aspect of the invention is that conduits of varying cross-sectionalareas may be placed in various sections of the lung to optimize theeffect of the collateral channels.

Another variation of the invention includes the application of acyano-acrylate, fibrin or other bio-compatible adhesive to maintain thepatency of a collateral channel. The adhesive may be used with orwithout the conduit described above. For example, the adhesive may bedeposited within the collateral channel to maintain patency of thechannel or to create a cast implant of the channel. The inventive actfurther includes the act of delivering medications such as steroidswhich have been shown to inhibit the healing process, bronchodilators,or other such drugs which aid in breathing, fighting infection, orrecovery from the procedure. The steroids inhibit inflammation and thenpromote the stabilization of the created channel.

Another variation of the inventive process includes promoting the flowof gasses through under-utilized parenchymal inter-conduits, orbypassing restricted airways. It is also contemplated that the gaseousflow may be altered by, for example, making separate inspiratory andexpiratory paths. Also, relieving pressure on the external wall of anatural airway may be accomplished to assist the natural airway bymaintaining patency during the expiration cycle of the lung. Yet anothervariation includes creating collateral channels parallel to existingairflow paths, or the existing airflow paths may be increased incross-sectional area.

The invention further includes a device for altering gaseous flow in adiseased lung comprising a locator for locating a site for collateralventilation of the lung, and optionally, a creating means for opening atleast one collateral channel at the site. It is contemplated that thedevice includes a means for locating a blood vessel as described above.Also, as stated above, the device may use a mechanical, electrical,laser, ultrasonic, microwave, or chemical process for creating acollateral channel. Another variation of the device includes a means forcoagulating blood upon the entry of the device into a blood vessel. Yetanother variation of the device includes the means for locating and themeans for creating are the same. The device may further include a meansfor simultaneously creating a plurality of collateral channels.

Another variation of the implant includes conduits constructed frommaterials that oppose the constriction of the natural airway over timeduring the expiration cycle of the lung. Yet another variation of theimplant includes a device which expands as the pressure in the lungdecreases during the expiration cycle.

The invention further includes a modified respiratory airway having anartificially created channel allowing gaseous communication between anexterior of the airway and an interior of the airway.

The invention may include an endoscope or a bronchoscope configured toselect sites and create collateral channels at those sites. An endoscopeor a bronchoscope may also be configured to deploy conduits within thecollateral channels. Another variation of the invention includes sizingthe device to fit within the working channel of a bronchoscope.

The invention also includes methods for evaluating an individual havinga diseased lung for a procedure to create collateral channels within anairway of the individual. The invention further includes the method ofdetermining the effectiveness of the procedure.

The invention further includes the act teaching any of the methodsdescribed above.

The invention further includes the method of sterilizing any of thedevices or kits described above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A-1C illustrates various states of the natural airways and theblood-gas interface.

FIGS. 1D-1G illustrate devices and methods for determining the degree ofcollateral ventilation within a lung.

FIG. 2A illustrates a natural airway with a collateral channel inrelation to a blood vessel.

FIGS. 2B-2K illustrate methods of avoiding blood vessel prior to thecreation of a collateral channel.

FIGS. 2B-2E illustrate various methods for delaminating an airway from ablood vessel.

FIG. 2F illustrates the use of a probe to determine a site for creatinga collateral channel.

FIGS. 2G-2K illustrate the use of sensors to determine a site forcreating a collateral channel.

FIGS. 3A-3I illustrate methods of and devices for creating a collateralopening within a natural airway.

FIGS. 3J-3K illustrate a method of folding epithelial tissue through acollateral channel.

FIG. 4 illustrates a device and method for simultaneously creatingnumerous collateral channels or deployment of numerous probes.

FIGS. 5A-5V illustrate various configuration of implantable conduits.

FIGS. 6A-6D illustrate devices for detecting blood vessels withintissue.

FIGS. 6E-6O illustrates various devices for detecting blood vesselswithin tissue where the devices also include hole-making assemblies.

FIGS. 6P-6V illustrate various electrode configurations for thehole-making assemblies of the device.

FIGS. 7A-7B illustrate devices and methods for creating a collateralchannel with a device having a hole-making assembly and also preservingthe tissue surrounding the collateral channel.

FIGS. 7C-7D illustrate additional electrode configurations for use witha device of the present invention where the structure of the electrodeslimits the possible depth of a collateral channel formed by theelectrode.

FIGS. 8A-8U illustrate variations of conduits of the present invention.

FIGS. 9A-9I illustrate variations of methods and devices for deploymentof conduits of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Prior to considering the invention, simplified illustrations of variousstates of a natural airway and a blood gas interface found at a distalend of those airways are provided in FIGS. 1A-1C. FIG. 1A shows anatural airway 100 which eventually branches to a blood gas interface102. FIG. 1B illustrates an airway 100 and blood gas interface 102 in anindividual having COPD. The obstructions 104 impair the passage of gasbetween the airways 100 and the interface 102. FIG. 1C illustrates aportion of an emphysematous lung where the blood gas interface 102expands due to the loss of the interface walls 106 which havedeteriorated due to a bio-chemical breakdown of the walls 106. Alsodepicted is a constriction 108 of the airway 100. It is generallyunderstood that there is usually a combination of the phenomena depictedin FIGS. 1A-1C. More usually, the states of the lung depicted in FIGS.1B and 1C are often found in the same lung.

The following illustrations are examples of the invention describedherein. It is contemplated that combinations of aspects of specificembodiments or combinations of the specific embodiments themselves arewithin the scope of this disclosure.

As will be explained in greater detail below, central to this inventionin all of its aspects is the production and maintenance of collateralopenings or channels through the airway wall so that expired air is ableto pass directly out of the lung tissue and into the airways toultimately facilitate exchange of oxygen into the blood and/ordecompress hyper inflated lungs. The term ‘lung tissue’ is intended toinclude the tissue involved with gas exchange, including but not limitedto, gas exchange membranes, alveolar walls, parenchyma and/or other suchtissue. To accomplish the exchange of oxygen, the collateral channelsallow fluid communication between an airway and lung tissue. Therefore,gaseous flow is improved within the lung by altering or redirecting thegaseous flow within the lung, or entirely within the lung. FIG. 1Dillustrate a schematic of a lung 118 to demonstrate a principle of theinvention described herein. As shown, a collateral channel 112 placeslung tissue 116 in fluid communication with airways 100 allowing expiredair to directly pass out of the airways 100. As shown, constrictedairways 108 may ordinarily prevent air from exiting the lung tissue 116.In the example illustrated in FIG. 1D, conduits 200 may be placed in thecollateral channels 112 to assist in maintaining the patency of thecollateral channels 112. Therefore, it is not necessary to pierce thepleura to improve gaseous flow within the lungs. While the invention isnot limited to the number of collateral channels which may be created,it is preferable that 1 or 2 channels are placed per lobe of the lung.For example, the preferred number of channels is 2-12 channels perindividual patient.

Accordingly, since the invention is used to improve the function of thelungs, a variation of the inventive device may include an endoscope or abronchoscope configured to locate a site for creating a collateralchannel and create the collateral channel. Another variation includessizing the inventive device to fit within a working channel of anendoscope or a bronchoscope. For the sake of brevity, hereafter, anyreference made to an endoscope includes the term bronchoscope.

The invention includes assessing the degree of the collateralventilation taking place in an area of a lung to select a site forcreation of a collateral channel. The invention may include locating asite for creation of a collateral channel by visually examining anairway for dynamic collapse. One method of visual examination includesthe use of a fiber optic line or camera which may be advanced into thelungs and through the airways. Other variations of visually examiningthe lung to determine the location of a site for the creation of thecollateral channel using non-invasive imaging, including but not limitedto radiography, computer tomography, ultrasound, Doppler, and acousticimaging. Such imaging methods may also be used to determine the amountof collateral channels to be created.

Also contemplated in the invention is the addition of various agents toassist during imaging of the airways or lungs. One example includes theuse of a non-harmful gas, such as Xenon, to enhance the visibility ofhyperinflated portions of the lung during radiological imaging. Anotherexample includes the use of inserting a fluid in the lungs to provide animproved sound transmission medium between the device and the tissue invariations of the invention using ultrasound, acoustic, or otherimaging.

Another variation of the invention includes methods and devices fortriggering a collapse of the airway to determine the degree ofcollateral ventilation in the lung. One example includes forcing afluid, such as a gas, air, oxygen, etc., through the airway and into theair sacs. Next, to assess the patency of the airway, the pressure isreduced in the airway. One example of how pressure is reduced in theairway includes evacuating the air in a direction opposite to the airsacs. Constriction of the airway given a drop in pressure may be anindication of collateral ventilation of the lung in that region.

FIG. 1E, illustrates a method and device 212 for causing collapse of theairway wall 100. The device 212 includes a fluid delivery member 214located at a distal end of the device 212. The fluid delivery member 214is configured to deliver a volume of fluid through the airway 100 andinto an air sac (not shown). The device 212 may also comprise a probe216 configured to collect data within the lung. The probe 216 may alsosimply consist of a channel that transmits signals outside of the lung.Moreover, the fluid delivery member 214 and the probe 216 may not beseparate channels. Also, the device 212 may, but does not necessarily,have an occlusion member 218 designed to isolate a section of the airway100 between the occlusion member 218 and the air sacs (not shown). Theocclusion member 218, which forms a seal against the airway 100 walls,may provide a partially closed system allowing a more effective searchfor collateral ventilation between the air sacs (not shown.) The devicedelivers a burst of fluid, through the fluid delivery member 214 andsubsequently uses the probe 216 to measure characteristics such aspressure, flow, or return volume to determine the degree of collateralventilation. The term fluid is intended to include, air or a gas, suchas oxygen, etc. For example, if the air sacs are diseased (as shown inFIG. 1C), the forced fluid will escape/disperse through another air sacdue to the collateral ventilation of the air sacs. As a result, theprobe 216 may fail to record any increase in pressure, volume, flow, orany other characteristic of the fluid at the site. Another variation ofthe invention includes using the fluid delivery member 214 to add orremove fluid distally to the occluded segment and using the probe 216 tomonitor flow or pressure changes in the area. For example, if afteradding/removing fluid the pressure in the occluded segment fails tobuild/drop, the assumption may be made that the gas is beingcollaterally vented through diseased air sacs.

FIG. 1F illustrates another variation of the invention. In this example,the device 220 comprises a separated probe 216 and gas delivery member214. In this variation, the fluid delivery member 214 is configured topass through a wall of the airway 100 so that fluid may be directlyforced into, or pulled out of an air sac 102.

FIG. 1G illustrates yet another variation of the invention. In thisvariation, the device 222 may have at least one fluid exchangepassageway 224. The device 222 may force fluid into the airway 100 viathe passageway 224. Then, fluid can be pulled out via the passageway224, thus decreasing pressure distally to the device 222. The decreasein pressure permits fluid to flow out of the airway 100 and away fromthe air sac (not shown). In this case, if the air sacs surrounding theairway 100 are diseased and collateral ventilation is taking place, thenthe airway 100 may collapse. A variation of the invention may include anexpandable member 218, such as a balloon, to create a seal against theairway 100 walls. Forming a seal may provide a partially closed systemto search for collateral ventilation between air sacs (not shown.) Asdescribed above, observation of a collapsing airway 100 may indicate adesired site for creation of a collateral channel.

FIG. 2A illustrates a blood vessel 110 on an outer wall of an airway100. In this figure, the collateral channel 112 created using thisinvention is located away from the vessel wall 110. Such a positioningof the collateral channel 112 eliminates the risk of rupturing thevessel 110 during formation of the collateral channel 112. As mentionedabove, the term channel is intended to include an opening, cut, slit,tear, puncture, or any other conceivable artificially created opening.

Of course, it is not the case that blood vessels are necessarily asconveniently located as is seen in FIG. 2A. Consequently, it may bedesirable to move the vessels or to avoid them. FIG. 2B illustrates afirst way of moving the nearby vessel. FIG. 2B shows the inflation ofthe airway 100 using a balloon 204 provided on a delivery device 202. Asshown in FIG. 2C, upon deflation of the balloon 204, the airway 100 andthe vessel 110 become delaminated thereby moving the vessel from theregion just outside the exterior of the airway. Subsequent creation of acollateral channel using the inventive procedures will be less likely tohit the vessel.

FIG. 2D demonstrates another device 206 and method for delaminating anairway 100 from a vessel 110. In this variation, the two balloons (204 &205) occlude the airway 100. As shown in FIG. 2E, upon application of avacuum, the vessel 110 and the airway 100 delaminate as the airway 100separates from the vessel 110. It may be desirable to make a channelwhile the airway is contracted as shown in FIG. 2E.

FIG. 2F illustrates the insertion of a probe 210 into a wall of theairway 100. Although, the probe 210 is illustrated to be a singularprobe, the delivery device 208 may be adapted to have multiple probes.As described above, the probe 210 may detect the presence of blood suchas when the probe is inserted into a vessel. For example, the probe 210could be configured to puncture a wall of the airway 100, and detect thepresence of blood. Optionally, the probe 210 could pull a vacuum tofacilitate entry of blood into the probe 210. The probe 210 may also useultrasonic detection to determine the location of a vessel. For example,ultrasound may be used to determine changes in composition of the tissuebeyond the airway wall for determination of the location of a vessel. Aprobe 210 may, for example, use low frequency radio energy to induceheat at a point and determine the presence of a vessel by measuring achange in temperature due to the conduction away or removal of heat bythe blood flowing within the vessel. Another variation is that the probe210 could detect changes in impedance given a pre-arranged discharge ofcurrent through the bloodstream. If a probe 210 detects blood during itstravel outside the airway, the user could select another spot for acollateral channel.

Another variation of the invention includes methods and devices fordetermining whether a blood vessel is in proximity to a potential site.Making this determination prior to creating the channel is advantageousas the risk of puncturing a blood vessel is minimized. As mentionedabove, non-invasive imaging may be used to locate blood vessels or toconfirm the absence of a vessel at a site. FIG. 2G illustrates anexample of this variation of the device 226 having a single sensor 228.The device may be, but is not necessarily, steerable and rotatable suchthat the sensor 228 can be placed in contact with any portion of theairway 100 wall. In non-steerable variations, the device may be locatedto a site by the use of an endoscope. The device 226 may also be stiffso that the sensor 228 may be placed in firm contact with a wall of theairway 100. It is important that the device does not ‘wander’ causingthe creation of a collateral channel at a distance from the areaoriginally searched. Such an occurrence may compromise a blood vessel(e.g., puncture, rupture, or otherwise open the blood vessel) eventhough the step of detecting the location indicated the absence of ablood vessel. In those cases, a stiffer wall provides added benefits.

Another variation of the invention includes inserting a fluid into theairway to provide a medium for the sensor 228 couple to the wall of theairway 100 to detect blood vessels. In those cases where fluid is notinserted, the device may use mucus found within the airway to directlycouple the sensor 228 to the wall of the airway 100.

FIG. 2H illustrates another variation of the inventive device 230 havinga plurality of sensors 228 arranged in an array pattern. Although notshown, the array could extend around the circumference of the device230. FIG. 21 illustrates yet another variation of the inventive device.In this example, the device 232 comprises a plurality of sensors 228arranged in a linear pattern. Although not shown, the pattern may alsowind helically or in other patterns around the perimeter of the device232.

FIG. 2J illustrates another variation of the invention. In this example,the device 234 comprises a sensor 228 encapsulated by an expandablemember 236 e.g., a balloon. The expandable member 236 may be filled witha fluid or other substance that couples the sensor 228 to an outersurface of the expandable member 236. The sensor 228 may be rotatablewithin the expandable member 236, or the entire device 234 may berotatable within the airway 100. Another variation of the device 234includes a mark 238 which provides a reference for orientation of thedevice 234 in the airway 100. The mark 238 is preferably remotelydetectable and may be positioned on the expandable member 236.

Another variation of the invention includes a means for marking thesite. This variation of the device allows marking of the site after itis located. Accordingly, once marked, a previously selected site can belocated without the need to re-examine the surrounding area forcollateral ventilation, or the presence or absence of a blood vessel.The marking may be accomplished by the deposit of a remotely detectablemarker, dye, or ink. Or, the marking may comprise making a physical markon the surface of the airway to designate the site. Preferably, the markis detectable by such imaging methods as radiography, computertomography (CT) imaging, ultrasound imaging, doppler imaging, acousticaldetection, or thermal detection or locating. Also, the mark may bedetectable by direct visualization such as the case when a fiber opticcable is used. FIG. 2K illustrates an example of the device 240 having asensor 228 to locate a site and a marking lumen 242 which may deposit anink, dye, or other marker (not shown) on the site once located.

Although not illustrated, the invention may include a user interfacewhich provides feedback once an acceptable site is located. For example,once a site is located a visual or audible signal or image istransmitted to the user interface to alert the user of the location of apotential site. The signal could be triggered once a blood vessel islocated so that the site is selected in another location. In anotherexample, the signal may trigger so long as a blood vessel is notlocated.

FIGS. 3A-3I depict various ways of providing openings in the airway wallwhich may be used as collateral air passageways.

FIG. 3A illustrates an airway 100 having a piercing member 300 and adilation member 302. In this example, the piercing member 300 makes anincision (not shown) in the airway 100 wall. Next, the piercing member300 is advanced into the wall so that a dilation member 300 can expandthe incision to thereby provide a collateral channel. In this example,the dilation member 300 is depicted as a balloon. One variation of theinvention includes filling a balloon with a heated fluid as the balloondilates the tissue to form the collateral channel. Use of a heatedballoon allows the transfer of heat to the collateral channel formodifying the healing response. However, it is also contemplated thatthe dilation member may be an expanding wedge (not shown) or othersimilar device.

FIG. 3B shows a cutting device 304 and an airway 100 having an opening306 cut from a wall. In this example, a flap 308 is cut from the walland is attached to an outside or an inside wall of the airway 100. Aswill be mentioned below, the flap may be glued, using for instance,fibrin-based or cyano-acrylate-based glues or stapled to that wall.

FIG. 3C illustrates a cutter 304 making an incision 310 in a wall of theairway 100. FIG. 3D illustrates one example of placing the walls of theairway 100 in tension and inserting a blunt instrument 314 into theincision. In this example, the delivery device 312 is flexible and maybe shaped to the contour of an airway 100 to provide support for theblunt instrument 314 so that the instrument 314 can advance into theincision. The delivery device 312 is also used to deliver a bluntinstrument 314 which expands the original incision. The blunt instrument314 may have a hooked configuration as needed.

FIG. 3E shows the use of a balloon 320 to dilate a previously formedcollateral channel in the airway wall 100. This procedure may be usedvariously with other mechanical, chemical, cryo-energy or RF basedpenetration systems to expand the size of that previously-formedopening.

FIG. 3F illustrates a variation of the device 322 having an RF electrode324. This variation of the invention uses RF energy to create acollateral channel. The device 322 may be mono-polar or bi-polar. The RFenergy throughout this invention is similar to that of a typical RFcutting probe operating between the 300 KHz-600 KEz range.

FIG. 3G-3I illustrates additional variations of devices of the presentinvention used to create collateral channels. The devices may use RFenergy, either monopolar or bipolar, or the devices may use light,infrared heat, or any of the other methods describe herein. In thevariation of FIG. 3G, the device 328 has an electrode 324 located on aside of the device. This variation of the device 328 automaticallylimits the depth of the collateral channel as the body of the device 328remains against an airway 100 wall while the electrode 324 creates achannel.

FIGS. 3H and 3I illustrates another variation of a device 330 of thepresent invention having an electrode 324 located on a front face of thedevice. FIG. 3I illustrates a perspective view of the device 330 with anelectrode on the front face 324. The device 330 may either have anelectrode 324 disposed on a front surface of the device 330 or thedevice may comprise a conductive material with an insulating layer 332covering the device 330 and leaving an electrode surface 324 exposed. Inthe variations illustrated in FIGS. 3G-3I, the size of the electrode maybe selected based upon the size of the desired collateral channel.

The device of the present invention may also be configured to limit thedepth of the collateral channel. In one example, the invention mayinclude a shoulder or stop 326 to limit the depth of the collateralchannel. Another example includes graduated index markings on a proximalend of the device or on the distal end so long as they are remotelydetectable. Also contemplated is the use of RF impedance measuring. Inthis example, the use of RF impedance may be used to determine when thedevice leaves the wall of the airway and enters the air sac or lessdense lung tissue.

The invention also includes creating a collateral channel by making asingle or a series of incisions in an airway wall then folding back thecut tissue through the collateral channel. This procedure allows thesurface epithelium which was previously on the inside of the airway wallto cover the walls of the newly formed collateral channel. As discussedherein, promoting growth of the epithelium over the walls of thecollateral channel provides a beneficial healing response. The incisionmay be created by the use of heat or a mechanical surface. For example,FIG. 3J illustrates a section of an airway 100 having several incisions356 forming a number of sections 358 of airway wall tissue the airway100. FIG. 3K illustrates the sections or flaps 358 of the airway wallfolded through the collateral channel 112. Any number of incisions 358may be made to form any number of sections 358 of airway wall tissue asdesired. For example, a plus-shaped incision would result in foursections of tissue that may be folded through a channel. The sections358 may be affixed with a suture material, an adhesive, or the sections358 may simply be inserted into surrounding tissue to remain foldedthrough the collateral channel 112.

Another variation of the device includes safety features such as probesto determine the presence of blood. If a probe indicates that a bloodvessel is contacted or penetrated, a signal is sent which prevents thechannel making device from causing further harm to the vessel. Such afeature minimizes the risk of inadvertently puncturing a blood vesselwithin the lungs.

Although the examples depict mechanically forming a collateral opening,the invention is not limited to such. Alternative methods of forming theopening are contemplated in the use of RF energy, bi-polar, or singlepole electrosurgical cutters, ultrasonic energy, laser, microwave,cryo-energy or chemicals.

The present invention includes the use of a device which is able todetect the presence or absence of a blood vessel by placing a frontportion of the device in contact with tissue. One variation of theinvention includes the use of Doppler ultrasound to detect the presenceof blood vessels within tissue. It is known that sound waves atultrasonic frequencies travel through tissue and reflect off of objectswhere density gradients exist. In which case the reflected signal andthe transmitted signal will have the same frequency. Alternatively, inthe case where the signal is reflected from the blood cells movingthrough a blood vessel, the reflected signal will have a shift infrequency from the transmitted signal. This shift is known as a Dopplershift. Furthermore, the frequency of the signals may be changed fromultrasonic to a frequency that is detectable within the range of humanhearing.

The ultrasound Doppler operates at any frequency in the ultrasound rangebut preferably between 2 Mhz-30 Mhz. It is generally known that higherfrequencies provide better the resolution while lower frequencies offerbetter penetration of tissue. In the present invention, because locationof blood vessels does not require actual imaging, there may be a balanceobtained between the need for resolution and for penetration of tissue.Accordingly, an intermediate frequency may be used (e.g., around 8 Mhz).

FIG. 6A illustrates a variation of a device 600 adapted to determine thepresence of blood vessels as previously mentioned. The device 600includes a flexible elongate member 604 having a transducer assembly606, at least a portion of which is located adjacent to a distal end ofthe elongate member 604. Although the elongate member 604 is illustratedas having a lumen, the elongate member 604 may also be selected to besolid, or the elongate member 604 may have a support member (not shown)such as a braid to increase the strength and/or maneuverability of thedevice. The transducer assembly 606 is adapted to generate a sourcesignal and receive a reflected signal. It may use a single transducer ormultiple transducers. For example, at least a first transducer may beused to generate a signal and at least a second transducer may be usedto receive the signal.

The transducer or transducers use may comprise a piezo-ceramic crystal.In the current invention, a single-crystal piezo (SCP) is preferred, butthe invention does not exclude the use of other types of ferroelectricmaterial such as poly-crystalline ceramic piezos, polymer piezos, orpolymer composites. The substrate, typically made from piezoelectricsingle crystals (SCP) or ceramics such as PZT, PLZT, PMN, PMN-PT Also,the crystal may be a multi layer composite of a ceramic piezoelectricmaterial. Piezoelectric polymers such as PVDF may also be used: Thetransducer or transducers used may be ceramic pieces coated with aconductive coating, such as gold. Other conductive coatings includesputtered metal, metals, or alloys, such as a member of the PlatinumGroup of the Periodic Table (Ru, Rh, Pd, Re, Os, Ir, and Pt) or gold.Titanium (Ti) is also especially suitable. For example, the transducermay befurther coated with a biocompatible layer such as Parylene orParylene C. The transducer is then bonded on the lens. A coupling suchas a biocompatible epoxy may be used to bond the transducer to the lens.The transducer assembly 606 communicates with an analyzing device 602adapted to recognize the reflected signal or measure the Doppler shiftbetween the signals. As mentioned above, the source signal may bereflected by changes in density between tissue. In such a case, thereflected signal will have the same frequency as the transmitted signal.When the source signal is reflected from blood moving within the vessel,the reflected signal has a different frequency than that of the sourcesignal. This Doppler effect permits determination of the presence orabsence of a blood vessel within tissue. Although depicted as beingexternal to the device 600, it is contemplated that the analyzing device602 may alternatively be incorporated into the device 600. Thetransducer assembly of the invention is intended to include anytransducer assembly that allows for the observation of Doppler effect,e.g., ultrasound, light, sound etc. The device 600 illustrated in FIG.6A includes a transducer assembly 606 comprising an ultrasoundtransducer 608 and an acoustic lens 610 that is adapted to refract anddisperse a source signal over an outer surface of the lens 610. The lens610 is designed such that it interferes and redirects the signals in adesired direction. The lens 610 may be comprised of materials such asdimethyl pentene (plastic-TPX), aluminum, carbon aerogel, polycarbonate(e.g., lexan), polystyrene, etc. It also may be desirable to place anepoxy between the lens 610 and the transducer 608. Preferably, the epoxyis thin and applied without air gaps or pockets. Also, thedensity/hardness of the epoxy should provide for transmission of thesignal while minimizing any effect or change to the source signal. Theconfiguration of the transducer assembly 606 permits the lens 610 todisperse a signal over a substantial portion of the outer surface of thelens 610. The lens 610 also is adapted to refract a reflected signaltowards the transducer 608. Accordingly, given the above describedconfiguration, the device 600 of FIG. 6A will be able to detect vesselswith any part of the lens 610 that contacts tissue (as illustrated bythe line 612-612.) Although the lens 610 is illustrated as beinghemispherical, as described below, the lens 610 may have other shapes aswell.

FIG. 6B illustrates another variation of the device 614 having ahemispherical shaped ultrasound transducer 618 affixed to an end of aflexible elongate member 616. The transducer 618 communicates with ananalyzing device (not shown) to measure the Doppler effect to determinethe location of a blood vessel.

FIG. 6C illustrates another variation of the device 620 including atransducer assembly 622, at least a portion of which is located adjacentto a distal end of the elongate member 628. The transducer assembly 622includes a flat ultrasound transducer 626, and a cone or wedge-likeacoustic mirror 624. The mirror 624 is adapted to reflect the signalover an area 360° around the device. The angle α of the mirror may bevaried to optimally direct the signal as needed.

FIG. 6D illustrates a variation of a device 630 of the present inventionfurther comprising a joint 632 to articulate an end of the device eitherto make sufficient contact with an area of tissue to be inspected forthe presence of a blood vessel, or to navigate within the body to accessthe area to be inspected.

The variations of the invention described herein may also be adapted touse ultrasound energy, for example, high energy ultrasound, to produceopenings in or marks on tissue. In such a case, the transducer assemblyand acoustic lens also functions as a hole-making or site markingdevice. In this case, use of ultrasound in a low power operation permitsthe detection of a blood vessel and location of a site for a collateralchannel. Using the same device and switching the operation of the deviceto a high power ultrasound permits the use of the ultrasound to create acollateral channel.

FIG. 6E illustrates a variation of a device 632 comprising a transducerassembly 634 connected to a flexible elongate member 636. In thisexample, the transducer assembly 634 comprises a first transducer 641, asecond transducer 642, and an acoustic lens 640. As mentioned above, invariations using alternate transducers 641, 642, one transducer maytransmit a signal while the other receives a signal. Also, bothtransducers 641, 642 may simultaneously transmit and receive signals. Itis intended that any combination of using the transducers to send andreceive signals is contemplated. The device 632 also includes ahole-making assembly 638 for creating a channel in tissue. FIG. 6Eillustrates the hole-making assembly 638 as an RF wire-like member. Asillustrated, the device 632 is connected an RF generator 644 as well asan analyzing device 646 which is adapted to measure the Doppler shiftbetween the generated and reflected signals.

FIG. 6F illustrates the device 632 of FIG. 6E where the hole-makingassembly 638 is retracted within the device 632, in this case within theelongated member 636.

FIG. 6G illustrates another variation of a device 648 where ahole-making assembly 650 is exterior to a transducer assembly 606. Thehole-making assembly 650 may be either an RF device or a mechanicaldevice that simply cuts the tissue. For example, the hole makingassembly 650 can be a hypotube placed over the transducer assembly 606.In this variation of the device 648, the transducer assembly 606 may bemoveable within the hole-making assembly 650, or the hole-makingassembly 650 may be moveable over the transducer assembly 606. In eithercase, the transducer assembly 606 may be advanced out of the hole-makingassembly 650 to determine the presence of a blood vessel. If no bloodvessel is found, the transducer assembly 606 may be withdrawn into thehole-making assembly 650 allowing the hole-making assembly 650 to createa channel in the tissue either by mechanically cutting the tissue, or byusing RF energy to create the channel. FIG. 6H illustrates a view takenalong the line 6H in FIG. 6G.

FIG. 6I illustrates another version of a device 652 of the presentinvention wherein the device has a transducer assembly 654 with anopening 658 through which a hole-making assembly 656 may extend. FIG. 6Jillustrates the hole-making assembly 656 extended through the transducerassembly 654. The hole-making assembly 656 may comprise RF electrodes orneedle-like members which puncture the tissue to create the channels.

FIG. 6K illustrates a variation of a device 666 of the present inventionwhere a tip 660 of the device has a conductive portion allowing the tipto serve as both an acoustic lens and an RF electrode. In such a case,the tip 660 is connected to an RF generator 644 for creating channelswithin tissue and a transducer 662 is placed in communication with ananalyzing device 646 that is adapted to measure the Doppler shiftbetween generated and reflected signals. In this variation, the tip 660is separated from the transducer 662, but both the tip 660 andtransducer 662 are in acoustic communication through the use of aseparation medium 664. The separation medium 664 transmits signalsbetween the tip 660 and the transducer 662. The spacing of thetransducer 662 from the tip 660 serves to prevent heat or RF energy fromdamaging the transducer 662. It is intended that the spacing between thetransducer 662 and tip 662 shown in the figures is for illustrationpurposes only. Accordingly, the spacing may vary as needed. Theseparation medium must have acceptable ultrasound transmissionproperties and may also serve to provide additional thermal insulationas well. For example, an epoxy may be used for the separation medium.

FIG. 6L illustrates a variation of a device 680 of the present inventionwherein the transducer assembly 670 comprises a tip 672, an ultrasoundcoupling medium 674, a transducer 676, and an extension member 678. Inthis variation of the invention, the tip 672 of the device serves as anacoustic lens and also has conductive areas (not shown) which serve asRF electrodes. As shown in FIG. 6M, the tip 672 may extend from thedevice 680 and separate from the transducer 676. Separation of the tip672 protects the transducer 676 from heat or RF energy as the tip 672creates a channel in tissue. The extension member 678 may serve as aconductor to connect the tip 672 to an RF energy supply (not shown).When the tip 672 of the device 680 is being used in an ultrasound mode,the tip 672 may be coupled to the transducer 676 via the use of anultrasound coupling medium 674. Any standard type of ultrasound gelmaterial may be used, also highly formable silicone may be used. It isdesirable to use a fluid boundary layer (such as the gel) which may bepermanent or temporary. In those cases where the boundary layer istemporary, subsequent applications of the boundary layer may benecessary.

FIG. 6N illustrates another variation of a device 682 of the presentinvention having a tip 684 and transducer 686 that are separable fromeach other. Again, the tip 684 may include conductive areas and serve asboth an RF electrode (not shown) as well as an acoustic lens. As shownin FIG. 6N, the tip 684 may be separable from the transducer 686 whencreating a channel to protect the transducer 686 from heat or RF energy.The tip 684 may be placed in contact with the transducer 686 foroperation in an ultrasound mode, or the device 682 may contain aseparation medium 688 which permits acoustic coupling of the transducer686 with the tip 684 when separated.

FIGS. 6P-6U illustrate variations of RF electrode tip 690 configurationsfor use with the present invention. As illustrated, the electrodes maybe placed around a circumference of a tip, longitudinal along a tip,spirally along a tip, or a combination thereof. The electrodes 692, 694may be used with a device having an acoustic lens or the electrodes maybe employed solely as an RF hole-making device. While the variationsillustrated in FIGS. 6P-6U show bipolar RF devices, the invention mayalso use a single electrode (monopolar.) The tip 690 may contain a firstelectrode 692 separated from a second electrode 694 by an electricalinsulator 696 (e.g., ceramic, or plastic insulator). In variations ofthe device where electrodes are positioned on an acoustic lens, asufficient amount of surface area of the lens must remain uncovered sothat sufficient coupling remains for transmission of a signal betweenthe lens and tissue. FIG. 6V illustrates a co-axial variation of abi-polar RF tip having a first electrode 692, a second electrode 694,and an insulator 696.

FIGS. 6W and 6X illustrates additional variations of the lens of thepresent invention. FIG. 6W illustrates a device 724 with an acousticlens 726 having an oblate spheroid shape. FIG. 6X illustrates a device728 with an acoustic lens 730 having a prolate spheroid shape. FIG. 6Yillustrates a device 732 having a conical-shaped acoustic lens 734.These variations are only intended to illustrate variations of the lens.It is contemplated that the shape of a lens may not follow amathematical description such as conical, prolate, oblate orhemispherical. The design of the shape relates to the distributionpattern of the signal over the lens. The shapes can affect thedistribution pattern by making it wider or narrower as needed. In anycase, the lens is of a shape that provides coverage over the front faceof the device.

FIG. 7A illustrates a variation of the invention where a device 700includes a heat-sink member 702. The heat-sink member 702 may preservesurround tissue during creation of the collateral channel. Or, theheat-sink member 702 may be a section of conductive material or aballoon. The heat-sink member 702 may be in fluid communication with alumen 704 that provides a fluid, such as saline, that conducts heat awayfrom the area surrounding the channel.

FIG. 7B illustrates another variation of a device 710 having a fluiddelivery assembly 706 which assists in preserving surrounding tissuewhile a channel is being created. The fluid delivery assembly 706 mayspray, mist, or otherwise apply fluid 708 to the area surrounding thechannel. For example, cooled saline may be applied to the area toprevent excessive heating of the target area.

The invention includes the use of hole-making assembly on the side ofthe device with a transducer assembly on the tip of the device. Forexample, FIG. 7C illustrates a variation of an RF electrode 712 for usewith the present invention. The electrode 712 may be a protrusionextending from a conductive member 716 that is covered with aninsulating material 714. In this variation, the electrode 716 limits thedepth of the channel due to the amount of material extending from theconductive member 716. The conductive member 716 may be connected to asource of RF energy (not shown) or may use another heating element (notshown). FIG. 7D illustrates another variation of an electrodeconfiguration. In this variation, the electrode comprises a sphericalmember 718 extending from an elongate member 722. The electrode 718 isretractable through the elongate member 722 by use of an actuator 720.The actuator 720 may be conductive and connected to a source of RFenergy to conduct energy through the electrode 718. Again, the design ofthe electrode 718 limits the depth of penetration of the electrode 718while creating a channel in tissue. The electrodes described herein mayalso be used in conjunction with a device having a Doppler arrangement.

Also, a variation of the invention contemplates the delivery of drugs ormedicines to the area of the collateral opening. Also contemplated isthe use of a fibrin, cyano-acrylate, or any other bio-compatibleadhesive to maintain the patency of the opening. For example, theadhesive could be deposited within the collateral channel to maintainpatency of the channel or to create a cast implant of the channel. Theadhesive could also coat the channel, or glue a flap to the wall of theairway. Also, the use of a bioabsorbable material may promote the growthof epithelium on the walls of the conduit. For example, covering thewalls of a channel with small intestine submucosa, or otherbioabsorbable material, may promote epithelium growth with thebioabsorbable material eventually being absorbed into the body.

FIG. 4 illustrates a variation of a device 400 having the ability tocreate multiple openings within the walls of the natural airway 100. Theholes may be created by dilation, cutting, electrical energy, microwaveenergy, ultrasonic energy, laser, chemical, or any process as mentionedabove. This device 400 may also be used to deploy multiple probes todetermine the location of a blood vessel (not shown) using one of theprocedures mentioned above.

FIG. 5A illustrates an implant or conduit 500 placed within a naturalairway 100. As shown, the airway 100 has a portion of its wall removed,thereby providing a collateral opening 112 within the airway 100. Theimplant 500 typically has a porous structure which allows gasses to passbetween the airway and the channels 112 and into the lung. Moreover, thestructure of the insert 500 also maintains patency of the airway 100 andthe channel 112.

Any variation of a conduit described herein may comprise a barrier layerwhich is impermeable to tissue. This aspect of the invention preventstissue in-growth from occluding the channel. The barrier layer mayextend between the ends of the body or the barrier layer may extend overa single portion or discrete portions of the body of the conduit.

FIG. 5B illustrates an conduit 500 having an expandable structure withinan airway 100. Usually, the conduit 500 has a porous wall that allowsthe passage of gasses through the wall. The conduit 500 is delivered viaa delivery device 502 which may also contain an expandable member (notshown) which expands the conduit 500. As shown in FIG. 5C, the conduitmay have piercing members 504 attached on an outer surface which enablethe conduit 500 to create an incision within the airway 100.

FIG. 5C illustrates the conduit 500 after being expanded by anexpandable member 506, e.g. a balloon device, an expandable mechanicalbasket, or an expandable wedge. In this example, the conduit 500 expandsthrough the walls of the airway 100 at sections 508. In this variation,the conduit 500 is lodged within the walls of the airway 100.

FIG. 5D illustrates a grommet-like insert 503 where the lumen of theinsert 503 extends longitudinally through the collateral channel. Inthis example, an expanding member 501, e.g., a balloon, an expandingmechanical basket, or the like is used to secure the conduit 503 withinthe collateral channel.

Although not illustrated, the invention includes conduits having alength to diameter ratio approximately 1:1. However, this ratio may bevaried as required. The cross-section of an implant may be circular,oval, rectangular, eliptical, or any other multi-faceted or curved shapeas required. The cross-sectional area of an implant 500 may be between0.196 mm¹ to 254 mm².

The conduit may also be any device capable of maintaining a patentopening, e.g., a plug, that is temporarily used as a conduit and thenremoved after the channel has healed in an open position. In anothervariation the plug may be a solid plug without an opening that is eitherbio-absorbable or removable. In such a case, the plug may be placedwithin an opening in tissue and allow the tissue to heal forming acollateral channel with the plug being ultimately absorbed into the bodyor removed from the body.

Another variation of the conduit is illustrated in FIG. 5E. In thisexample the conduit 510 comprises a cone 514 with a grommet 512 forattachment to a wall of the airway 100. The cone 514 may be porous orhave other openings 516 to facilitate the passage of gas through thecollateral channel. In the event that the distal opening of the conebecome occluded, the porous cone permits the continued exchange ofgasses between the collateral channel and the natural airway.

Another variation of the conduit is illustrated in FIG. 5F. For example,the conduit 518 may be configured in a ‘t-shape’ with a portion 520 ofthe conduit extending through the collateral channel. Again, the conduit518 may be constructed to have a porous wall to allow gas exchangethrough the wall. The conduit may be configured in a variety of shapesso long as a portion of the conduit extends through the collateralchannel. The portion may be formed into a particular shape, such as the‘t-shape’ described above, or, the portion may be hinged so that it maybe deployed within the channel. In such a case, a portion of a wall ofthe conduit may have a hinge allowing the wall of the conduit to swivelinto a channel.

Yet another variation of the conduit is found in FIG. 5G. In thisexample, the conduit 522 is constructed with a geometry that reduces thechance that the conduit 522 will migrate within the airway 100.

FIG. 5H illustrates an example of a conduit 524 having an asymmetricalprofile. The conduit 524 may have a flange 526 at either or both ends ofthe body 528. Although not shown, the flange 526 may have a cone-likeprofile to facilitate placement within an airway. As illustrated in FIG.51, the asymmetrical profile of the conduit 524 assists in preventingobstruction of the airway.

FIG. 5J illustrate a variation of the conduit 530 having a self-cleaningmechanism. In this example, the self cleaning mechanism is a floatingball bearing 532. The ends of the conduit 530 have a reduced diameter534 which prevents the bearing 532 from escaping. As gas passes throughthe conduit 530, the bearing 532 moves about the conduit 530 clearing itof debris. The shape of the bearing 532 and the size and shape of thereduced diameter 534 may be varied to optimize the self-cleaning effectof the device.

FIGS. 5K and 5L illustrate another variations of a self-expandingconduit 536. In this example, as shown in FIG. 5K, the conduit 536 maybe constructed from a flat material 538 having a spring or springs 540.As shown in FIG. 5L, the conduit 536 is formed by rolling the assembly.The spring 540 provides an expanding force against the material 538. Theconduit 536 may also be constructed so that the flat material 538 isresilient thus eliminating the need for springs 540.

FIG. 5M illustrates another variation of an expandable conduit 542constructed from a braided material. The conduit 542 may be constructedso that the diameter is dependent upon the length of the device 542. Forexample, the diameter of the device 542 may decrease as the length isstretched, and the diameter may increase as the length of the device 542is compressed. Such a construction being similar to a ‘finger cuff’ toy.

FIGS. 5N-5P illustrate another variation of a grommet-type conduit. FIG.5N illustrates a conduit 544 having expandable ends 546. In onevariation the ends 546 of the device 544 may flare outwards asillustrated in FIG. 50. FIG. 5P illustrates another variation of thedevice 544 in which the ends 546 compress in length to expand indiameter.

FIGS. 5Q and 5R illustrate variations of a conduit having an anchor. InFIG. 5Q, the conduit 548 has an anchor 550 at a distal end of a hollowplug 540. The anchor 550 may be tapered to facilitate entry into theairway 100 wall or may have another design as required. The anchor 550also contains ventilation openings 552 to facilitate gas exchangethrough the device. FIG. 5R illustrates another variation of the device.

FIG. 5S illustrates a variation of a conduit 561 having flanges 563 ateither end to assist in placement of the conduit within an airway wall(not shown). The ends of the conduit 565 may be tapered to easeplacement through a collateral channel. The conduit has an opening 565to facilitate passage of air. To simplify construction, the conduit 561may be constructed from a biocompatible material, such as stainlesssteel, or plastic.

FIG. 5T illustrates a variation of the invention having multipleopenings for gas flow. The conduit 560 has a first hollow end 564 whichcan extend through a wall of the airway 100 and a second hollow end 566which can remain parallel to the airway 100. This example also includesan opening 562 which allows gas to flow through the airway 100.

FIG. 5U illustrates a variation of the device having a one-way valve570. The valve 570 allows the conduit 568 to permit exhaust of the airsac but prevents the conduit 568 from serving as another entrance of gasto the air-sac. The valve 570 may be placed at ends of the conduit orwithin a lumen of the conduit. The valve 570 may also be used asbacterial in-flow protection for the lungs.

FIG. 5V illustrates another variation of a conduit 572. In thisvariation, the conduit 572 may be a sponge material, or constructed ofan open cell material 574, which allows air flow through the material.Or, the conduit 572 may have lumens 576 which allow flow through theconduit 572. To assist the conduit 572 in remaining within a channel,the conduit material may be selected such that it expands as it absorbsmoisture. Also, the sponge material/open cell material may bebio-absorbable to allow for temporary placement of the conduit 572.

FIGS. 8A-8F illustrate another variation of a conduit 800 of the presentinvention. The conduit 800 has a center section 802 having extensionmembers 804 located at either end of the center section 802. The centersection 802 illustrated is tubular but may be of any other shape asneeded for the particular application. The conduit of the invention hasa passageway extending between the ends of the conduit suited for thepassage of air. The variation of the conduit 800 illustrated in FIG. 8Ahas a center section 802 comprising a mesh formed from a plurality ofribs 806. FIGS. 8A and 8B illustrate the conduit 800 in a reducedprofile while FIGS. 8C and 8D illustrate the conduit 800 in an expandedprofile after expansion of the center section 802 of the conduit 800. Asshown in FIGS. 8E and 8F, each free end 808 of each extension member 804is unattached to the center section 802 and is bendable about therespective end of the center section 802 to which it is attached.Accordingly, once a conduit 800 is placed within a collateral channel(not shown), the extension members 804 are bent about the end of thecenter section 802 and form a cuff or grommet which assists in keepingthe conduit 800 within a collateral channel. Accordingly, the crosssection and number of extension members 804 located about either end ofthe conduit 800 may be selected as necessary to assist in placement andsecuring of the conduit 800 within a channel.

The conduits described herein may have a fluid-tight covering, asdiscussed below, about the center section, the extension members, or theentire conduit. Also, the conduit may be designed to limit a length ofthe center section to less than twice the square root of a crosssectional area of the center section when the center section is in theexpanded profile.

FIG. 8G-8I illustrates another variation of a conduit 812 for use withthe invention. In this variation, the conduit 812 is formed from arolled sheet of material 810. The rolled sheet 810 may be heat treatedto preserve the shape of the conduit 812 or the sheet 810 may simply berolled to form the conduit 812. In those cases where the sheet ofmaterial 810 comprises a shape-memory alloy, it is desirable to processthe material 810 so that it exhibits super-elastic properties at orabove body temperature.

FIG. 8G illustrates a variation of extension members 820 for use with aconduit (not shown) of the present invention. In this variation, theextension members 820 have an attachment 822 between adjacent extensionmembers 820. FIG. 8H illustrates the extension members 820 as theconduit (not shown) is expanded and the extension members 820 are benton the conduit. The attachment 822 assists in preventing the extensionmembers 820 from deviating from a preferred position. As illustrated inFIG. 81, the conduit 826 may have cut or weakened sections 824 tofacilitate expansion of the conduit 826 and bending of the extensionmembers in a desired manner (as shown by the section of 828).

FIGS. 8J-8K illustrate various additional cross sectional designs ofconduits. FIG. 8J illustrates a possible conduit design 830 havingextension members 834 attached to a center section 832. FIGS. 8K and 8Lillustrate additional variations of conduit designs. As illustrated inFIGS. 8K and 8L, the extension members 840, 846 and center sections 838,844 are designed to form a diamond pattern upon expansion of theconduit. FIG. 8K further illustrates a variation of an extension member840 having an opening 841 to facilitate tissue in-growth and therebysecures placement of the conduit. FIG. 8M illustrates an expandedconduit 848 having the diamond pattern referred to above. The conduit848 also contains a fluid-tight barrier 851 on the center section 850 ofthe conduit 848. Although not illustrated, fluid-tight barrier may beplaced throughout a conduit. Another feature of the variation of FIG. 8Mis that the extension members have a diamond pattern construction, thisconstruction assists in maintaining alignment of the extension membersallowing for a preferred aligned expansion of the extension members.

FIGS. 8N-8O illustrate another variation of a conduit 860 of the presentinvention. In this variation, the conduit design 854 may have extensionmembers 856 at only one end of the conduit 860. In this variation, thecenter section of the conduit may comprise a body portion 858. Theconduit 860 may have a covering about a portion of the conduit 860. Thecovering may extend throughout the length of the conduit 860 or it maybe limited to a portion of the conduit 860. As illustrated in FIG. 8O,when expanded, the conduit 860 may form a reduced area 858 near theextension members 856. As mentioned above, the conduit cross section 854may be designed such that the a diamond pattern is formed upon expansionof the conduit 860, as illustrated in FIG. 8O.

FIG. 8P illustrates a sheet of material 810 having extension members 814extending from either end of the sheet 810. Although the sheet 810 isillustrated to be solid, a conduit may be formed from a sheet havingopenings within the center section of the sheet. FIG. 8Q illustrates theconduit 812 where the rolled sheet 810 comprises a center section 818 ofthe conduit 812 and the extension members 814 from either end of thecenter section 818. As illustrated in FIG. 8Q, the sheet 810 may beoverlapped for a reduced profile and expanded into an expanded profile.FIG. 8R illustrates a free end 816 of each extension member 814 ashaving been bent away from a central axis of the conduit 812. As withany variation of a conduit of the present invention, the extensionmembers 814 of the conduit 812 may be bent away from a central axis ofthe conduit 812 up to 180° with respect to the central axis. Asmentioned above, the cross section and number of extension members 814located about either end of the conduit 810 may be selected as necessaryto assist in placement and securing of the conduit 810 within a channel.

In those cases where the conduit 812 of FIG. 8Q comprises a non-shapememory alloy the conduit 812 will be actively mechanically expanded. Inthose cases where the conduit 812 is comprised of a shape memory alloy,such as a super-elastic alloy, the conduit 812 may be pre-formed toassume a deployed shape which includes a grommet formed by extensionmembers 814 and an expanded center section 818, such as the shapeillustrated in FIG. 8R. Next, the super-elastic conduit 812 may berestrained or even rolled into the shape illustrated in FIG. 8Q. Becausethe conduit 812 is formed of a super-elastic material, no plasticdeformation occurs. When the super-elastic conduit 812 is then placedwithin a collateral channel, the conduit 812 may naturally resume itspre-formed, deployed shape.

FIG. 8S illustrates another variation of a conduit 862 having a firstportion 864 and a second portion 866 and a passageway 868 extendingtherethrough. The first portion 864 may be a conduit design as describedherein. In particular, the first portion 864 is configured to secure theconduit 862 to the airway wall 100. Accordingly, the first portion 864may or may not have a center that is expandable. The walls of the firstportion 864 may be fluid-tight (either through design, or a fluid tightcovering) to prevent tissue in-growth through the collateral channel.Alternatively, the first portion 864 may be partially fluid-tight tofacilitate tissue in-growth to improve retention of the conduit 862 tothe airway wall 100. However, in the latter case, the first portion 864should be designed to minimize tissue in-growth within the channel toprevent substantial interference with airflow through the conduit 864.As with the first portion 864, the walls of the second portion 866 ofthe conduit may or may not be fluid-tight. If the second portion 866 isnot fluid-tight, the larger area provides for improved airflow from lungtissue through the passageway 868 and into the airway. The secondportion 866 may also be designed to be partially fluid-tight toencourage airflow through the conduit 862 but reduce the probability ofblockage of the conduit 862.

FIGS. 8T-8U illustrate another variation of a conduit 870. For example,the conduit 870 may be formed from a tube that is slit to form extensionmembers at a first portion 872 and second portion 876 with a centersection 874 between the portions. The conduit 870 may be expanded asshown in FIG. 8U such that the first 872 and second 876 portionsmaintain the center portion 874 in a collateral channel in an airwaywall. The center section 874 may or may not be expandable.

FIG. 8U illustrates the second portion 876 of the conduit 870 to expandin its center, however, the conduit 870 may be designed in otherconfiguration as well (e.g., expanded to have a larger diameter at anend opposite to the center section 874.) However, a central aspect ofthis design is that the second portion 870 provides a large area in thelung tissue to permit a larger volume of air to pass from the lungtissue into the conduit 870. This design has an added benefit as thesecond portion 876 cannot be easily blocked by flaps of parenchymatissue. A simple variation of the conduit 870 may be constructed from ametal tube, such as 316 stainless steel, titanium, titanium alloy,nitinol, etc. Alternatively, the conduit may be formed from a rigid orelastomeric material.

The conduits described herein may be comprised of a metallic material(e.g., stainless steel), a shape memory alloy, a super-elastic alloy(e.g., a NiTi alloy), a shape memory polymer, a polymeric material or acombination thereof. The conduit may be designed such that its naturalstate is an expanded state and it is restrained into a reduced profile,or, the conduit may be expanded into its expanded state by a variety ofdevices (e.g., a balloon catheter.) The conduit described herein may bemanufactured by a variety of manufacturing processes including but notlimited to laser cutting, chemical etching, punching, stamping, etc.

The conduits described herein may be coated with an elastomer, e.g.,silicone, polyurethane, etc. The coatings may be applied, for example,by either dip coating, molding, or liquid injection molding (forsilicone). Or, the coating may be a tube of a material and the tube isplaced either over and/or within the conduit. The coating(s) may then bebonded, crimp, heated, melted, or shrink fit. The coatings may alsoplaced on the conduit by either solvent swelling applications or by anextrusion process. Also, a coating of may be applied by either wrappinga sheet of PTFE about and/or within the conduit, or by placing a tubeabout and/or within the conduit and securing the tubes.

As mentioned above, the number of and cross sectional area of theextension members on a conduit may be selected as needed for theparticular application. Also, the extension members may be bent suchthat they anchor into the tissue thereby securing placement of theconduit. Or, the extension members or the center section may containbarbs or other similar configurations to better adhere to the tissue.Moreover, the orientation of the extension members may vary as well. Forexample, the extension members may be configured to be radiallyexpanding from the center section, or they may be angled with respect toa central axis of the conduit. Another variation of the inventionincludes a radioactive conduit which inhibits or prevents the growth oftissue within the conduit.

Although the conduits of the current invention have been described tocontain expandable center sections, the invention is not necessarilylimited as such. Instead, the design of the conduit may requireextension members on the ends of a conduit with a non-expandable centersection.

FIGS. 9A-9D illustrate a conduit 900 of the present invention. Thedeployment of the conduit 900 is intended to show an example of apossible means of deployment only. Accordingly, the inventive conduitmay be delivered at an angle via an articulating or jointed device, theconduit may be delivered on a device that is adapted to locate andcreate the collateral channel, or the conduit may be delivered on adevice having other features as needed for the particular application.

FIG. 9A illustrates the conduit 900 being delivered to a collateralchannel in an airway wall 114 via a delivery device (e.g., a ballooncatheter 902.) The conduit 900 may be attached to the delivery device902 using the natural resiliency of the conduit 900. Or, in those caseswhere the conduit is spring loaded, the conduit 900 restrained in areduced profile and may be removably affixed to the delivery device 902using an adhesive, or a removable sleeve such as a heat shrink tube. Inthis example, the balloon catheter 902 has several balloons including adistal balloon 904, a proximal balloon 906, and a center balloon (notillustrated in FIG. 9A). FIG. 9B illustrates the inflation of the distal904 and proximal 906 balloons to situate the extension members 908.Accordingly, the extension members 908 for a flange or collet about theairway wall 114. The balloons 904, 906 may be inflated simultaneously,or in a desired sequence. In any case, deployment of the balloons 904,906 may serve to center the conduit 900 in the collateral channel.

FIG. 9C illustrates inflation of the center balloon 912 which causesexpansion of the center section 910 of the conduit 900. If the conduit900 is affixed to the delivery device 902, expansion of the centerballoon 912 causes release of the conduit 900 by release of the adhesiveor breaking of the heat shrink tubing (not shown). In any case, themeans of attachment may be bioabsorbable and remain in the body, or mayremain affixed to the delivery device 902 and is removed with removal ofthe delivery device 902. FIG. 9D illustrates the conduit 900 affixed tothe airway wall 114 after the delivery device 902 is removed from thesite. Another method of deploying a conduit includes restraining theconduit about a delivery device using a wire or string tied in aslip-knot or a series of slip-knots. When the conduit is delivered to adesired location, the proximal end of the wire or string may be pulledwhich releases the wire/string and deploys the conduit. FIGS. 9E and 9Fillustrate possible ways to manipulate a conduit 914 for placement in anairway wall 114 using a delivery device 916. FIG. 9E illustratesdeployment of a delivery device 916 to place a conduit 914 within anopening in an airway wall 114. The conduit 914 may be placed over aballoon 918 (or other expandable section) of the delivery device 916.FIG. 9F illustrates deployment of the balloon 918 to place and expandthe conduit 914. In the variation illustrated in FIGS. 9E and 9F, aballoon 918 serves several functions. The balloon 918 first expands andstarts bending the extension members 920. The balloon 918 continues tocenter the conduit 914 on the tissue and simultaneously begins to expandthe conduit 914 and secures the conduit to the tissue.

FIGS. 9G and 9H illustrate additional variations of deployment devices.In these variations, the deployment devices 922, 926 containhourglass-shaped balloons 924, 928. The hour glass-shaped balloons 924,928 contain an interior profile 923. For deployment of a conduit (notshown) of the present invention, the conduit is placed on the balloon924, 928. As the balloon 924, 928 expands, the conduit expansion matchesthe interior profile 923 of the balloon 924, 928. Accordingly, the hourglass-shaped balloon 924, 928 may be used to set the angle andorientation of the expandable members of a conduit as well as theexpansion of a center section of the conduit.

FIG. 91 illustrates another variation of an hour glass shaped balloondelivery device 930. This variation of the hour glass shaped balloon 932is designed to expand extension members (not shown) of a conduit (notshown) at a particular angle 934. The orientation of the balloon 932 maybe designed as needed to impart the desired angle to the extensionmembers of the conduit. The balloons described herein may be constructedpolyethylene terephthalate (PET) or any other material which is used inthe construction of balloon catheters.

The invention further includes methods of evaluating individuals havinga diseased lung to assess inclusion of the individual for the procedure.

The method comprises the steps of performing pulmonary function tests onthe individual. The pulmonary function tests may obtain such values asFEV (forced expiratory volume), FVC (forced vital capacity),FEF_(25%-75%) (forced expiratory flow rate), PEFR (peak expiratory flowrate), FRC (functional residual capacity), RV (residual volume), TLC(total lung capacity), and/or flow/volume loops.

FEV measures the volume of air exhaled over a pre-determined period oftime by a forced expiration immediately after a full inspiration. FVCmeasures the total volume of air exhaled immediately after a fullinspiration. FEF_(25%-75%) measures the rate of air flow during a forcedexpiration divided by the time in seconds for the middle half of expiredvolume. PEFR measures the maximum flow rate during a forced exhalestarting from full inspiration. FRC is the volume of air remaining inthe lungs after a full expiration. RV is the FRC minus the expiratoryreserve volume. TLC is the total volume in the lungs at the end of afull inspiration. Flow/volume loops are graphical presentations of thepercent of total volume expired (on the independent axis) versus theflow rate during a forced expiratory maneuver.

The invention further comprises methods to determine the completion ofthe procedure. This variation of the invention comprises the step ofperforming pulmonary function tests as described above, creatingcollateral channels in the lungs, performing a post-procedure pulmonaryfunction test, obtaining clinical information, comparing the results ofthe tests, evaluating the clinical information with the results of thetest to determine the effectiveness of the procedure.

Another method to determine the completion of the procedure includeschecking the resistance of airflow upstream from a location of acollateral channel. The method includes making a collateral channel,checking airflow, measuring resistance to airflow, and repeating theprocedure until acceptable resistance is obtained. Because thecollateral channel allows for the release of trapped air, the resistanceto airflow should decrease. A body plethysmograph or other suitableequipment used to measure in pulmonary medicine may be used to determinethe resistance to airflow.

A measurement of total lung volume may be used to determine when thelung is suitably deflated and therefore when enough collateral channelsare created. Or, non-invasive imaging may be used to determine pre andpost procedure lung volume or diaphragm position.

An evaluation of the effectiveness of the procedure may also includecreating a collateral channel then sealing the channel with a ballooncatheter. The distal end of catheter is then opened for a measurement ofthe flow of trapped air through the catheter.

This variation of the invention includes obtaining clinical informationregarding the quality of life of the individual before and after anyprocedures, physical testing of the pulmonary system of the individual,and a general screening for pulmonary condition.

The invention herein is described by examples and a desired way ofpracticing the invention is described. However, the invention as claimedherein is not limited to that specific description in any manner.Equivalence to the description as hereinafter claimed is considered tobe within the scope of protection of this patent.

1. A method of improving gaseous flow within a lung having chronicobstructive pulmonary disease comprising placing an implant in an airwayof the lung to allow expired air to pass out of the lung tissue.
 2. Themethod of claim 1, further comprising locating at least one regionwithin a portion of a natural airway of the respiratory system foraltering gaseous flow.
 3. The method of claim 2, comprising creating atleast one channel at a site in the region.
 4. The method of claim 3,comprising locating a region for altering gaseous flow prior to the stepof locating.
 5. The method of claim 3, wherein the locating stepincludes examining the lung using an imaging method selected fromradiography, computer tomography, ultrasound, Doppler, and acousticimaging to determine a location to alter the gaseous flow.
 6. The methodof claim 1, further comprising delivering drugs to the airway.
 7. Themethod of claim 1, further comprising the step of delivering steroids tothe lung.
 8. The method of claim 1, wherein the conduit is comprised ofa material selected from the group consisting of elastomers, polymers,metals, metal alloys, shape memory alloys, and shape memory polymers. 9.The method of claim 1, wherein the conduit is removable from the body.10. The method of claim 1, comprising creating at least one channelwithin the lung.
 11. The method of claim 1, wherein the conduit isadapted to maintain the patency of the natural airway duringconstriction of the airway.